BY-COVID - WP5 - Baseline Use Case: COVID-19 vaccine effectiveness assessment

Descriptive analyses

Periods

Period Time range
Data extraction period 2020-03-05 - 2022-05-20
Enrollment period 2021-01-01 - 2021-08-31
Study period 2021-01-01 - 2022-08-31

Study population and enrollment

Description of the study population: table 1

Table 1
Intervention group
(N=8126)		 Control group
(N=8126)		 P-value

ᵃ5-year age groups
sex_cd
Mean (SD) 1.46 (0.537) 1.45 (0.549) 0.175
Median [Min, Max] 1.00 [0, 2.00] 1.00 [0, 2.00]
age_cdᵃ
Mean (SD) 11.6 (2.96) 11.6 (2.99) 0.622
Median [Min, Max] 12.0 [2.00, 18.0] 12.0 [2.00, 18.0]
residence_area_cd
731 1133 (13.9%) 1170 (14.4%) 0.00829
732 1144 (14.1%) 1011 (12.4%)
733 5849 (72.0%) 5945 (73.2%)
institutionalized_bl
Yes 225 (2.8%) 219 (2.7%) 0.81
No 7901 (97.2%) 7907 (97.3%)
foreign_bl
Yes 1234 (15.2%) 1231 (15.1%) 0.965
No 6892 (84.8%) 6895 (84.9%)
pregnancy_bl
Yes 97 (1.2%) 83 (1.0%) 0.33
No 8029 (98.8%) 8043 (99.0%)
essential_worker_bl
Yes 226 (2.8%) 224 (2.8%) 0.962
No 7900 (97.2%) 7902 (97.2%)
comorbidities_bl
Yes 3736 (46.0%) 3723 (45.8%) 0.85
No 4390 (54.0%) 4403 (54.2%)
immunestatus_bl
Yes 2280 (28.1%) 2287 (28.1%) 0.917
No 5846 (71.9%) 5839 (71.9%)

Tables

The individuals in the imported dataset are counted by ‘fully_vaccinated_bl’ and ‘confirmed_case_bl’.

Not completed a primary vaccination schedule Completed a primary vaccination schedule Total
No confirmed case 639 6010 6649
Confirmed case 361 2990 3351
Total 1000 9000 10000

Ratio = \(\frac{(\frac{confirmed \ cases}{non-vaccinated \ individuals})} {(\frac{confirmed \ cases}{vaccinated \ individuals})}\) = 0.9202832

The individuals eligible for analysis are counted by ‘fully_vaccinated_bl’ and ‘confirmed_case_bl’.

Not completed a primary vaccination schedule Completed a primary vaccination schedule Total
No confirmed case 620 5739 6359
Confirmed case 329 2639 2968
Total 949 8378 9327

Ratio = \(\frac{(\frac{confirmed \ cases}{non-vaccinated \ individuals})} {(\frac{confirmed \ cases}{vaccinated \ individuals})}\) = 0.9085929

The matched individuals are counted by ‘fully_vaccinated_bl’ and ‘confirmed_case_bl’.

Not completed a primary vaccination schedule Completed a primary vaccination schedule Total
No confirmed case 558 5705 6263
Confirmed case 237 2613 2850
Total 795 8318 9113

Ratio = \(\frac{(\frac{confirmed \ cases}{non-vaccinated \ individuals})} {(\frac{confirmed \ cases}{vaccinated \ individuals})}\) = 1.0537541

Survival in un-matched population

Variable Beta (SE) HR (95% CI) P
fully_vaccinated_blTRUE -0.02 (0.07) 0.98 (0.86, 1.11) 0.71

Strata Time Number at risk Number of events Number censored Survival Std. error Cumulative hazard Std. error cumulative hazard
Not fully vaccinated 0 902 1 0 0.9988914 0.0011080327 0.0011086475 0.0011086475
Not fully vaccinated 100 887 14 0 0.9833703 0.0042579213 0.0167601671 0.0043275070
Not fully vaccinated 200 881 6 0 0.9767184 0.0050209720 0.0235436859 0.0051377719
Not fully vaccinated 300 869 12 0 0.9634146 0.0062511087 0.0372477521 0.0064843714
Not fully vaccinated 400 693 179 0 0.7649667 0.0141183086 0.2674750096 0.0184246060
Not fully vaccinated 500 621 69 0 0.6884701 0.0154201697 0.3726241520 0.0223575550
Not fully vaccinated 600 620 1 0 0.6873614 0.0154351407 0.3742344580 0.0224154712
Fully vaccinated 0 8378 1 0 0.9998806 0.0001193531 0.0001193602 0.0001193602
Fully vaccinated 100 8253 125 0 0.9849606 0.0013297021 0.0151514274 0.0013498093
Fully vaccinated 200 3885 468 3997 0.9149921 0.0034433135 0.0887960657 0.0037611165
Fully vaccinated 300 2645 478 668 0.7759389 0.0065510625 0.2534754869 0.0084351389
Fully vaccinated 400 2307 123 220 0.7394797 0.0070201758 0.3015773379 0.0094855960
Fully vaccinated 500 786 5 1561 0.7378440 0.0070426699 0.3037910797 0.0095371385
Fully vaccinated 600 7 0 725 0.7378440 0.0070426699 0.3037910797 0.0095371385
Variable Beta (SE) HR (95% CI) P
fully_vaccinated_blTRUE -0.02 (0.07) 0.98 (0.86, 1.11) 0.73
age_cd 0.00 (0.01) 1.00 (0.99, 1.02) 0.64
sex_cd -0.05 (0.05) 0.95 (0.86, 1.04) 0.26
residence_area_cd
     731 (ref) – – –
     732 0.04 (0.10) 1.04 (0.85, 1.28) 0.67
     733 0.14 (0.08) 1.15 (0.99, 1.34) 0.07
essential_worker_blTRUE 0.03 (0.15) 1.03 (0.76, 1.39) 0.84
institutionalized_blTRUE 0.20 (0.14) 1.22 (0.92, 1.61) 0.17
foreign_blTRUE -0.04 (0.07) 0.96 (0.83, 1.11) 0.60
comorbidities_blTRUE 0.02 (0.05) 1.02 (0.92, 1.13) 0.75
immunestatus_blTRUE 0.01 (0.06) 1.01 (0.90, 1.13) 0.93